GBase 8s V8. 8 SQL Guide: Tutorial - 6.2.1 (3)

The self join in the following query is in stock Create a list of those goods supplied by three manufacturers in the table . Self connect in
WHERE Clause includes the last two conditions , To remove the duplicate manufacturer code retrieved in the line .
chart : Inquire about
SELECT s1.manu_code, s2.manu_code, s3.manu_code, 
 s1.stock_num, s1.description
 FROM stock s1, stock s2, stock s3
 WHERE s1.stock_num = s2.stock_num
 AND s2.stock_num = s3.stock_num
 AND s1.manu_code < s2.manu_code
 AND s2.manu_code < s3.manu_code
 ORDER BY stock_num;
chart : Query results
manu_code manu_code manu_code stock_num description
 
 HRO HSK SMT 1 baseball gloves 
 ANZ NRG SMT 5 tennis racquet 
 ANZ HRO HSK 110 helmet
 ANZ HRO PRC 110 helmet
 ANZ HRO SHM 110 helmet
 ANZ HSK PRC 110 helmet
 ANZ HSK SHM 110 helmet
 ANZ PRC SHM 110 helmet
 HRO HSK PRC 110 helmet
 HRO HSK SHM 110 helmet
 HRO PRC SHM 110 helmet
 ⋮
 KAR NKL PRC 301 running shoes
 KAR NKL SHM 301 running shoes
 KAR PRC SHM 301 running shoes
 NKL PRC SHM 301 running shoes